1. Field of the Invention
The invention relates to a driving assistance apparatus and a driving assistance method that assist driving of a movable body such as a vehicle.
2. Description of the Related Art
Technologies for assisting driving of a vehicle and the like are available. For example, Japanese Patent Application Publication No. 2002-230682 (JP-A-2002-230682) describes a system in which it is determined whether a vehicle can be automatically driven. In the system, calculations are performed to determine whether a steering operation can be performed, whether a deceleration operation can be performed, and whether an acceleration operation can be performed, based on, the amount of steering of the vehicle and a vehicle speed. Thus, it is determined whether the vehicle can be automatically driven. In the system, if it is determined that the vehicle cannot be automatically driven, a change of a driving mode to an automatic driving mode is stopped, and the vehicle is manually driven.
In the system, when a driving assistance control for automatic driving or the like ends, the driver of the vehicle may feel discomfort. For example, if the driving mode is suddenly changed to the automatic driving mode at the start of the driving assistance control, the driver may feel discomfort because driving operation performed by the driver is not reflected in a manner in which the vehicle travels. The driver may also feel discomfort when the automation level of the automatic driving control is changed during the automatic driving control.